I wonder if this is your issue?
I found this CentOS forum thread titled: [SOLVED] User input during rc.local?.
excerpt of problem
I'm attempting to mount an encrypted drive during the execution of the rc.local file. It prompts for a password, but upon the second keypress, it appears to be receiving a crlf (or whatever) and attempts to unlock the drive - failing, since I wasn't silly enough to encrypt it with a two character passcode.
To which the apparent answer is to disable
You cannot run interactive scripts from rc.local unless you first run 'plymouth quit'.
excerpt from Freedesktop.org
Plymouth is an application that runs very early in the boot process (even before the root filesystem is mounted!) that provides a graphical boot animation while the boot process happens in the background.
It is designed to work on systems with DRM modesetting drivers. The idea is that early on in the boot process the native mode for the computer is set, plymouth uses that mode, and that mode stays throughout the entire boot process up to and after X starts. Ideally, the goal is to get rid of all flicker during startup.
Solving your issue
So I believe all you'd need to do is prior to running your
read command is to make use you put in
rc.local the command: